Oilfield activities involve various sub-activities used to locate and gather valuable hydrocarbons. Various tools, such as seismic tools, are often used to locate the hydrocarbons. One or more drilling operations may be positioned across an oilfield to locate and/or gather the hydrocarbons from subterranean reservoirs of an oilfield. The drilling operations are provided with tools capable of advancing into the ground and removing hydrocarbons from the subterranean reservoirs. Once the drilling operation is complete, production facilities are positioned at surface locations to collect the hydrocarbons from the wellsite(s). Fluid is drawn from the subterranean reservoir(s) and passed to the production facilities via transport mechanisms, such as tubing. Various equipment is positioned about the oilfield to monitor and manipulate the flow of hydrocarbons from the reservoir(s).
During oilfield activities, it is often desirable to monitor various oilfield parameters, such as fluid flow rates, flow pressures, etc. Sensors may be positioned about the oilfield to collect data relating to the wellsite and the processing facility, among others. For example, sensors in the wellbore may monitor flow pressure, sensors located along the flow path may monitor flow rates, and sensors at the processing facility may monitor fluids collected. The monitored data is often used to make real-time decisions at the oilfield. Data collected by these sensors may be further analyzed and processed.
The processed data may be used to determine conditions at the wellsite(s) and/or other portions of the oilfield, and to make decisions concerning these activities. Operating parameters, such as wellsite setup, drilling trajectories, flow rates, wellbore pressures, and other parameters, may be adjusted based on the received information. In some cases, known patterns of behavior of various oilfield configurations, geological factors, operating conditions or other parameters may be collected over time to predict future oilfield activities.
Oilfield data are often used to monitor and/or perform various oilfield activities. Numerous factors may be considered in operating an oilfield. Thus, the analysis of large quantities of a wide variety of data is often complex. Over the years, oilfield applications have been developed to assist in processing data. For example, simulators, or other scientific applications, have been developed to take large amounts of oilfield data and to model various oilfield activities. Typically, there are different types of simulators for different purposes. Examples of these simulators are described in patent/application Nos. U.S. Pat. No. 5,992,519, WO2004049216, and U.S. Pat. No. 6,980,940.
Numerous oilfield activities, such as drilling, evaluating, completing, monitoring, producing, simulating, reporting, etc., may be performed. Typically, each oilfield activity is performed and controlled separately using separate oilfield applications that are each written for a single purpose. Thus, many such activities are often performed using separate oilfield applications. In some cases, it may be necessary to develop special applications, or modify existing applications to provide the necessary functionality.
For instance, fractures are often induced hydraulically in low-permeability reservoirs to boost hydrocarbon flow. To fracture the rock, a fluid is injected into the rock at a high pressure. Proppant, such as sand of a particular size, is then injected into the fracture to keep it open and enhance hydrocarbon flow into the wellbore. Hydraulic fracturing is sometimes performed on very thick pays. As a result, fractures are induced in stages along the length of a wellbore, creating multiple reservoir zones along the wellbore. Data from the fractured wellbore is then collected and analyzed by an oilfield application to characterize the various reservoirs and completions.
Wells with very different fracture and reservoir characteristics may display very similar performances. This is known as non-uniqueness. Current production analysis techniques for single fracture wells may be used to analyze multilayer wells. However, the results give only the effective properties of an equivalent single-layer reservoir. Consequently, a method that can be used to make decisions regarding stimulation effectiveness for individual layers of a multilayer reservoir is needed.